Organic light emitting display and method for manufacturing the same

ABSTRACT

Disclosed are an organic light emitting display that has a configuration excluding a polarizing plate and exhibits improved flexibility and visibility, and a method for manufacturing the same, the organic light emitting display includes a touch electrode array facing the organic light emitting diode on the second buffer layer, the touch electrode array including first and second touch electrodes intersecting each other and an exterior light shielding layer including at least a color filter layer, an adhesive layer formed between the organic light emitting diode and the touch electrode array.

The present patent document is a divisional of U.S. patent applicationSer. No. 13/718,391, filed Dec. 18, 2012, which claims benefit to KoreanPatent Application No. 10-2012-0096740, filed on Aug. 31, 2012, which ishereby incorporated by reference as if fully set forth herein.

BACKGROUND

1. Field of the Disclosure

The present disclosure relates to an organic light emitting display, andmore particularly, to an organic light emitting display that has aconfiguration excluding a polarizing plate and exhibits improvedflexibility and visibility, and a method for manufacturing the same.

2. Discussion of the Related Art

Examples of flat panel displays include liquid crystal displays (LCDs),organic light emitting displays (OLEDs), plasma display panels (PDPs),quantum dot panels (FDPs), field emission displays (FEDs),electrophoretic displays (EPDs) and the like. These displays include aflat display panel realizing an image in common as an essentialcomponent. In such a flat display panel, a pair of transparentinsulating substrates are joined together such that they face each othervia a layer containing an inherently luminescent or polarizing materialor other optical material interposed therebetween.

In accordance with the recent trend toward large-size displays, demandhas gradually increased for flat panel displays that occupy a smallerspace. Of these flat panel displays, organic light emitting displaytechnologies are being rapidly developed.

Organic light emitting displays do not require any separate light sourceand include an organic light emitting diode that spontaneously emitslight in each pixel, to realize display. The organic light emittingdisplays attract much attention as next-generation displays since theyadvantageously do not require light sources as well as structures forassembling the light sources with a display panel, thus havingadvantages of decrease in thickness and weight.

When electric charges are injected into an organic film formed betweenan electron injection electrode (cathode) and a hole injection electrode(anode), electrons pair with holes and the pairs then decay. At thistime, an organic light emitting diode emits light.

There is an increasing demand for an organic light emitting display of atouchscreen in which a site touched by the hand or separate inputelement is sensed and information is transferred in response thereto.Such a touchscreen is typically applied by adhesion to the outer surfaceof the display.

Depending on touch sense method, a touchscreen is divided intoresistive, capacitive and infrared sensing types. In consideration ofease of manufacture, sensing force and the like, capacitive typetouchscreens attract much attention in small models.

Hereinafter, a touchscreen-integrated organic light emitting display ofrelated art will be described with reference to the annexed drawings.

FIG. 1 is a sectional view illustrating a touchscreen-integrated organiclight emitting display of related art.

As shown in FIG. 1, the touchscreen-integrated organic light emittingdisplay of related art includes an organic light emitting display panel1, a touchscreen 2 and a cover window 3 laminated in this order from thebottom and includes first and second adhesive layers 15 and 25 disposedbetween the respect layers.

Here, the organic light emitting display panel 1 includes a substrate, athin film transistor array having a matrix form disposed on thesubstrate, and an organic light emitting diode connected to each thinfilm transistor of the thin film transistor array, and includes aprotective film and a polarizing layer that cover the top of the organiclight emitting diode. In this case, the first adhesive layer 15corresponds to the polarizing layer of the organic light emittingdisplay panel 1. Also, the second adhesive layer 25 is formed betweenthe touchscreen 2 and the cover window 3 to adhere the touchscreen 2 tothe cover window 3.

The touchscreen-integrated organic light emitting display has thefollowing disadvantages.

First, in a case in which an organic light emitting display panel and atouchscreen are independently formed and the touchscreen is thenattached to the organic light emitting display panel, the organic lightemitting display panel and the touchscreen require separate glasses,thus causing increase in hardness and thickness, which makes realizationof thin and flexible organic light emitting displays impossible.

Second, the organic light emitting display panel and the touchscreenhave different panel shapes, thus making processes for forming thesecomponents complicated and thus decreasing yield and pricecompetiveness.

Third, a polarizing plate is provided in order to prevent recognition ofexterior light of the organic light emitting display panel. Thepolarizing plate has a thickness of about 150 μm or more, is expensiveand causes a deterioration in transmittance. Accordingly, since thepolarizing plate deteriorates flexibility when used for displays and isexpensive, other alternative capable of preventing deterioration invisibility is required.

SUMMARY

An organic light emitting display includes: a first buffer layer and asecond buffer layer facing each other; a thin film transistor arrayincluding a thin film transistor in each of a plurality of pixelsdefined in a matrix on the first buffer layer; an organic light emittingdiode connected to a thin film transistor of each pixel; a touchelectrode array facing the organic light emitting diode on the secondbuffer layer, the touch electrode array including first and second touchelectrodes intersecting each other, and an exterior light shieldinglayer including at least a color filter layer; an adhesive layer betweenthe organic light emitting diode and the touch electrode array; a coverglass on a rear surface of the second buffer layer; and a film substrateon a rear surface of the first buffer layer.

In accordance with another aspect of the present invention, provided isa method for fabricating an organic light emitting display including:forming a first etch stopper film and a first buffer layer on a firstsubstrate, and forming a thin film transistor array including a thinfilm transistor in each of a plurality of pixels defined in a matrixform and an organic light emitting diode connected to a thin filmtransistor of each pixel in an active region of the first buffer layer;forming a second etch stopper film and a second buffer layer on a secondsubstrate; forming a touch electrode array facing the organic lightemitting diode on the second buffer layer, wherein the touch electrodearray includes first and second touch electrodes intersecting eachother, and an exterior light shielding layer including at least a colorfilter layer; joining the first and second substrates via an adhesivelayer between the organic light emitting diode and the touch electrodearray; removing the first substrate and the second substrate; andadhering a film substrate to the exposed first etch stopper film andcovering the exposed second etch stopper film with a cover glass.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andsimultaneously with the description serve to explain the principle ofthe invention. In the drawings:

FIG. 1 is a sectional view illustrating a touchscreen-integrated organiclight emitting display of related art;

FIG. 2 is a plan view illustrating an organic light emitting displayaccording to an embodiment of the present invention;

FIG. 3 is a sectional view taken along the line of FIG. 2;

FIG. 4 is an enlarged plan view of a region “A” of FIG. 2;

FIG. 5 is a sectional view taken along the line of FIG. 4 according to afirst embodiment of the present invention;

FIG. 6 is a view illustrating a process of forming a touch electrodearray of an organic light emitting display according to the presentinvention;

FIGS. 7A to 7E illustrate a touch electrode array according to anorganic light emitting display according to another embodiment;

FIG. 8 is a sectional view illustrating an organic light emittingdisplay according to a modified embodiment of the present invention; and

FIG. 9 is a reference embodiment of the present invention compared withthe organic light emitting display in terms of visibility.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

Hereinafter, an organic light emitting display and a method formanufacturing the same will be described in detail with reference to theannexed drawings.

In recent years, there has been an increasing demand for touch sensingas well as thinness and flexibleness of organic light emitting displays.In response to this, a method in which a thin film transistor and anorganic light emitting array are formed on a first substrate, a touchelectrode array is formed on a second substrate, these substrates arejoined together, and the hard and thick first and second substrates areremoved by laser irradiation or etching in order to realize thin filmand flexibility is suggested. In this case, a pad portion of the touchelectrode array faces a pad portion of the organic light emitting array,and these pad portions are connected to each other via a conductiveball, thus enabling transfer of signals to the touch electrode array anddetection of signals from the touch electrode array.

Hereinafter, an in-cell organic light emitting display in which a touchelectrode array is provided inside a cover glass will be described.

FIG. 2 is a plan view illustrating an organic light emitting displayaccording to the present invention. FIG. 3 is a sectional view takenalong the line I-I′ of FIG. 2.

As shown in FIG. 2 and FIG. 3, the organic light emitting displayaccording to the present invention has a configuration in which anorganic light emitting array 150 and a touch electrode array 230, thatare formed at an inside of a film substrate 1000 and at an inside of acover glass 3000, respectively, and have different sizes, are joined toeach other via an adhesive layer 400.

Also, the organic light emitting display according to the presentinvention excludes a polarizing plate under a cover glass, and furtherincludes an exterior light shielding layer 2400 including a black matrixlayer (represented by “242” in FIG. 5) and a color filter layer(represented by ″242 in FIG. 5) in the touch electrode array thatperforms a function of preventing recognition of exterior light, insteadof the polarizing plate. The black matrix layer and the color filterlayer prevent emission of incident light in order to prevent exteriorlight incident upon the organic light emitting display from beingreflected and be seen by a viewer. A detailed description of the touchelectrode array having this configuration will be provided withreference to FIG. 5.

These arrays are not directly formed on the film substrate 1000 or thecover glass 3000 and are obtained by separately preparing first andsecond substrates (both, not shown), each being made of glass, joiningthe substrates via an adhesive layer disposed between the organic lightemitting array 150 and the touch electrode array 230 (that is, thisjoining process is performed while keeping the first and secondsubstrates), and removing the first and second substrates by laserirradiation or etching for realization of thin film and flexibility. Inthis case, as shown in FIG. 2, the first and second substrates formed ofglass materials are removed and the film substrate 1000 and the coverglass 3000 are adhered to the bottom of the exposed arrays,respectively, in order to protect these arrays.

A film adhesive layer 1100, a first etch stopper layer 120, a firstbuffer layer 130 and a thin film transistor array 140 and an organiclight emitting array 150 are formed on the film substrate 1000 in thisorder and a protective layer 160 is formed to cover the organic lightemitting array 150. A second etch stopper layer 210, a second bufferlayer 220 and a touch electrode array 230 are disposed on the coverglass 3000. The touch electrode array 230 is disposed to face theorganic light emitting array 150. In this case, the protective layer 160directly contacts the bottom of the adhesive layer 400 and the touchelectrode array 230 directly contacts the top thereof.

An active region and a dead region are defined in the first buffer layer130 and the second buffer layer 220, respectively, and the touchelectrode array 230, the organic light emitting array 150 and thin filmtransistors present in the thin film transistor array 140 excluding apad portion are formed in the active region. Also, the touch electrodepad portion 2350 and the pad portion of the thin film transistor arrayare defied in part regions of the dead region.

The first etch stopper layer 120 and the second etch stopper layer 210function to prevent damage to an internal array, in addition to theglass materials of first and second substrates during laser irradiationor etching. If desired, the first and second buffer layers 130 and 220disposed thereunder are not damaged during removal of the first andsecond substrates, the first and/or second etch stopper layers 120 and210 may be omitted.

Also, the first buffer layer 130 and the second buffer layer 220 may beformed by sequentially laminating the same type of inorganic film suchas an oxide film (SiO₂) or nitride film (SiNx), or alternativelylaminating different types of inorganic films. The first and secondbuffer layers 130 and 220 serve as barriers that prevent permeation ofmoisture or exterior air into the organic light emitting array 150 afterthe second substrate is joined to the first substrate.

Also, both the touch pad portion 2350 and the touch electrode array 230are formed on the same surface of the second buffer layer 220.

The touch pad portion 2350 is connected to the pad portion of the thinfilm transistor array 140 via a sealant 450 including a conductive ball455, when the upper and lower substrates are joined to each other viathe adhesive layer 400. The adhesive layer 400 functions to preventpermeation of moisture and directly contacts the protective layer 160that covers the organic light emitting array 150, thus preventingpermeation of exterior air into the organic light emitting array 150 andmore certainly prevents permeation of moisture, in addition to thefunctions of the protective layer 160.

The thin film transistor array 140 including the pad portion has a sidethat protrudes from the touch electrode array 230. This configurationaims at providing, at the protrusion, an IC 500 that transfers a signalto simultaneously drive the touch electrode array and the thin filmtransistor array, and the organic light emitting array. Although notshown, the IC 500 is connected through lines (not shown) formed on theIC 500 and the first buffer layer 130 to driving pads and dummy pads ofthe thin film transistor array. Also, the IC 500 is bonded and connectedto a flexible printed circuit board (FPCB, not shown) and may becontrolled by a controller (not shown) provided in the FPCB. The dummypad is formed in the same layer as a metal constituting a gate or dataline in a region corresponding to the touch pad portion among the deadregion disposed out of the active region.

The touch pad portion 2350 is formed on the second buffer layer 220 andis formed at both edges of the side adjacent to a portion where thefirst buffer layer 130 protrudes more than the second buffer layer 220.Also, the touch pad portion 2350 formed at one edge is divided into aplurality of pad electrodes to enable voltage application or detectionof first electrodes arrayed in an X-axis direction in the touchelectrode array, and the touch pad portion 2350 formed at the other edgeis divided into a plurality of pad electrodes to enable voltageapplication or detection of second electrodes arrayed in an Y-axisdirection.

The conductive ball 455 connected to the touch pad portion 2350 iselectrically connected to a dummy electrode (not shown) formed out ofthe thin film transistor array 140.

During an actual process, the adhesive layer 160 and the sealant 450 areseparately formed by application to different regions.

Meanwhile, as shown in FIG. 3, the organic light emitting displayaccording to the present invention includes a film substrate 1000, afirst etch stopper film 120 and a first buffer layer 130 formed in thisorder on the film substrate 1000, a thin film transistor array 140having a thin film transistor in each pixel defined in a matrix form onthe first buffer layer 130, an organic light emitting array 150connected to the thin film transistor of each pixel, a protective layer160 that covers the thin film transistor array 140 excluding the padportion and the organic light emitting array 150, a touch electrodearray 230 adhered to the protective layer via an adhesive layer 400interposed between the protective layer 160 and the touch electrodearray 230, and a second buffer layer 220 and a second etch stopper film210 formed in this order on the touch electrode array 230, and includesa cover glass 3000 disposed on the second etch stopper film 210.

The cover glass 3000 may be adhered to the second etch stopper film 210via an adhesive layer interposed between the second etch stopper film210 and the cover glass 3000, or may be disposed on the second etchstopper film 210 by a mechanical method or another method. The coverglass 3000 prevents damage to internal array from direct touch of a userand protects the internal array therefrom.

The organic light emitting display according to the present inventioncan be reduced in thickness by omitting a glass substrate having athickness of about 0.7 mm, which is the thickest of components in thedisplay, and can realize a bendable or flexible display using the filmsubstrate 1000 as a plastic insulating film that functions to supportthe thin film transistor array 140, the organic light emitting array 150and the touch electrode array 230.

In addition, in the process of forming arrays such as the thin filmtransistor array 140, the organic light emitting array 150 and the touchelectrode array 230 on the film substrate, the film substrate isthermally expanded by heat applied to apparatuses for depositing orpatterning the arrays, thus making normal processing impossible. Inorder to prevent this phenomenon, substantially, formation of arrays iscarried out by forming etch stopper films 120 and 210 and buffer layers130 and 220 under the thin film transistor array 140 and the touchelectrode array 230, respectively, on the glass substrate, beforeformation of the thin film transistor array 140 and formation of thetouch electrode array 230, and then loading the glass substrate in anapparatus for deposition or patterning.

Meanwhile, the thin film transistor array 140 includes a plurality ofgate lines and a plurality of data lines that intersect each other todefine pixels, and thin film transistors formed at the respectiveintersections between the gate lines and the data lines. A pad portionof the thin film transistor array 140 is obtained by forming a padportion metal in the process of forming the gate and data lines.

Also, the organic light emitting array 150 includes a first electrodeformed at least in the pixel, a second electrode formed in an upperlayer spaced from the first electrode, and an organic light emittinglayer formed between the first and second electrodes. The firstelectrode may be connected to a drain electrode of the thin filmtransistor.

In addition, the first etch stopper film 120 and the second etch stopperfilm 210 may be for example formed of polyimide or photo-acryl.

The first and second etch stopper films 120 and 210 have a thickness ofabout 1 μm to about 20 μm.

Also, the first buffer layer 130 and the second buffer layer 220function to prevent permeation of oxygen or moisture into organic filmsprovided in the organic light emitting array and serve as barriers thatprevent permeation of exterior air or moisture injected from a lowerpart.

The first buffer layer 130 and the second buffer layer 220 include aplurality of inorganic films. For example, the inorganic films may beformed by continuously or alternatively laminating SiNx or SiO2. It canbe seen from experimentation that, when two or more layers are laminatedto a thickness of about 5,000 Å to 6,500 Å as the first and secondbuffer layers 130 and 220, permeation of exterior air or moisture can beprevented. A total thickness of the first and second buffer layers 130and 220 is 1 μm or less, which does not increase the thickness of thetouchscreen-integrated display device.

Hereinafter, a configuration of the touch electrode array according tothe present invention will be described in detail.

FIG. 4 is an enlarged plan view of a part “A” of FIG. 2. FIG. 5 is asectional view taken along the line II-II′ of FIG. 4 according to afirst embodiment of the present invention.

As shown in FIGS. 4 and 5, the touch electrode array 230 according tothe first embodiment of the present invention includes a first touchelectrode and a second touch electrode intersecting each other, and atouch pad 2351 b (provided in a touch pad portion 2350) transferring asignal to the first and second touch electrodes. The touch pad 2351 bmay be connected to a dummy pad (not shown) formed in the dead region ofthe thin film transistor array. FIG. 3 illustrates a thin filmtransistor array 140 including the dummy pad, and a touch electrodelayer as one layer including the touch pad, and first and second touchelectrodes 2331 and 2332. These layers are patterned according toindividual electrodes.

The first touch electrode is disposed in a first direction and includesa first electrode pattern 2331 disposed in an island form and a metalbridge 231 to electrically connect the first electrode pattern 2331 toanother first electrode pattern 2331 adjacent to a layer different fromthe first electrode pattern, and the second touch electrode is disposedin a direction intersecting the first direction and includes a secondelectrode pattern 2332 having the same shape as the first electrodepattern 2331 and a connection pattern 2332 c to connect adjacent secondelectrode patterns 2332 in an integrated form with the second electrodepattern.

The first electrode pattern 2331, the second electrode pattern 2332 andthe connection pattern 2332 c are formed as the same transparentelectrode in a first layer, the metal bridge 231 is formed in a secondlayer on a first interlayer insulating film 232 interposed between thefirst layer and the second layer, and the first interlayer insulatingfilm may include a contact hole 232 a in a region where the metal bridge231 overlaps the second electrode patterns 2332.

In the drawing of FIG. 5, the first layer corresponds to the surface ofthe first interlayer insulating film 232 and the second layercorresponds to the second buffer layer 220. This shows an example inwhich the metal bridge 231 is formed on the second buffer layer 220, afirst interlayer insulating film 232 including a contact hole 232 a isthen formed, the first electrode pattern 2331, and the second electrodepattern 2332 and the connection pattern 2332 c are then formed, althoughthe present invention is not necessarily limited thereto. If desired,formation order of the metal bridge 231 and the first and secondelectrode patterns 2331 and 2332 and connection pattern 2332 c may bechanged.

Also, an exterior light shielding layer 2400 including a black matrixlayer 242 and a color filter layer 241 is formed on the first interlayerinsulating film 232 including the first and second electrode patterns2331 and 2332 and the connection pattern 2332 c.

The black matrix layer 242 absorbs light and blocks transmission oflight, and is formed on the edge of respective pixels of the thin filmtransistor array and the organic light emitting diode that face thetouch electrode array 230.

Also, a red pigment layer (R), a green pigment layer (G) and a bluepigment layer (B) constituting the color filter layer 241 correspond topigment layers that transmit light having the same color as lightemitted from the light emitting layer of the organic light emittingdiode in respective pixels. For example, in a pixel in which the lightemitting layer of the organic light emitting diode is a red lightemitting layer, the red pigment layer (R) corresponds to the red lightemitting layer, in a pixel in which the light emitting layer is a greenlight emitting layer, the green pigment layer (G) corresponds to thegreen light emitting layer, and in a pixel in which the light emittinglayer is a blue light emitting layer, the blue pigment layer (B)corresponds to the blue light emitting layer.

Meanwhile, as shown in FIG. 4, the first interlayer insulating film 232is exposed on a neighboring portion of touch pads 2351 b in the touchpad portion 2350. This means that the neighboring portion has a steplower than the touch pad 2351 b including electrodes, transparentelectrodes and the like which are laminated. This step makes the levelof the touch pad 2351 b higher, makes the conductive ball 455 compressedduring bonding and thereby facilitates contact between the touch pad2351 b and the conductive ball 455.

FIG. 6 is a view illustrating a process of forming a touch electrodearray of an organic light emitting display according to the presentinvention.

As shown in FIG. 6, formation of the touch electrode array 230 of theorganic light emitting display is carried out on a second buffer layer220 after sequentially forming a second etch stopper film 210 and thesecond buffer layer 220 on a second substrate 200.

As described above, the second buffer layer 220 is a laminate having athickness of 1 μm including a plurality of inorganic films. In order toprevent damage from heat, etching solution or the like applied duringformation of the array, an array formation process is not directlyperformed on the second buffer layer 220 and an array formation processis performed on the second substrate 200 made of a glass component.

After the touch electrode array 230 is joined to the organic lightemitting array 150 such that these arrays face each other, the firstsubstrate (not shown) and the second substrate 200 made of glasscomponents are removed by etching using an etching solution or throughlaser irradiation. At this time, the second etch stopper film 210prevents damage to the first and second buffer layers 130 and 220 andarrays disposed thereon. As described above, the first and second etchstopper films 120 and 210 may be organic film components resistant toetching solution or laser irradiation. However, the first and secondetch stopper films 120 and 210 have a thickness of 20 μm or less andthus neither increase the thickness of the device nor deteriorateflexibility.

Meanwhile, the exterior light shielding layer 2400 including the blackmatrix layer 242 and the color filter layer 241 may have other shapes.

Hereinafter, another embodiment of the touch electrode array includinganother form of exterior light shielding layer will be described.

FIGS. 7A to 7E illustrate a touch electrode array according to anorganic light emitting display according to another embodiment.

FIG. 7A illustrates a touch electrode array of an organic light emittingdisplay according to the second embodiment of the present invention.Comparing the second embodiment with the first embodiment, the secondembodiment further comprises common transparent electrode patterns 235 aand 235 b that cover the second interlayer insulating film 234 and thefirst electrode pattern 2331, the second electrode pattern 2332 and theconnection pattern 2332 c on the first interlayer insulating film 232including the first electrode pattern 2331, the second electrode pattern2332 and the connection pattern 2332 c.

The first electrode pattern 2331 is covered with the first commontransparent electrode pattern 235 a and the second electrode pattern2332 and the connection pattern 2332 c which are integrated with eachother are covered with the second common transparent electrode pattern235 b.

Also, the exterior light shielding layer 3400 including the black matrixlayer 342 and the color filter layer 341 is formed on the secondinterlayer insulating film 234 including the common transparentelectrode pattern 235 a.

As shown in FIG. 2, the common transparent electrode pattern 235 ablocks effects of a signal transferred from the organic light emittingarray 150 or the thin film transistor array 140 disposed in a lower parton driving of the touch electrode array 230, when the touch electrodearray 230 contacts the protective film 160 covering the organic lightemitting array 150 via an adhesive layer 400. The common transparentelectrode pattern 235 a has a floating state, which stabilizes drivingof the first touch electrode and the second touch electrode disposedtherein without application of exterior voltage.

FIG. 7B illustrates a touch electrode array of an organic light emittingdisplay according to a third embodiment of the present invention. Incomparison with the second embodiment, the third embodiment includes ashielding layer 2400 including the black matrix layer 242 and the colorfilter layer 241, instead of the second interlayer insulating film 234.In this case, the second interlayer insulating film 234 may be omitted,and the process of the first embodiment is simplified, as compared tothe second embodiment.

FIG. 7C illustrates a touch electrode array of an organic light emittingdisplay according to a fourth embodiment of the present invention. Incomparison with the second embodiment, the third embodiment includes ashielding layer 2400 including the black matrix layer 442 and the colorfilter layer 441, instead of the first interlayer insulating film 232.In this case, the first interlayer insulating film 232 may be omitted,and the process of the first embodiment can be simplified, as comparedto the second embodiment.

FIG. 7D illustrates a touch electrode array of an organic light emittingdisplay according to a fifth embodiment of the present invention. Incomparison with the second embodiment, the fifth embodiment includes acolor filter layer 541 including a red pigment (R), a green pigment (G)and a blue pigment (B), instead of the first interlayer insulating film232.

In the fifth embodiment, a contact hole 232 a is formed in the colorfilter layer 541, the first electrode pattern 2331 connected to themetal bridge 231 through the contact hole 232 a, the second electrodepattern 2332 which is spaced from the first electrode pattern 2331 andis disposed in a direction intersecting the disposition direction of thefirst electrode pattern 2331, and a connection pattern 2332 c integratedtherewith are formed on the color filter layer 541. Also, at the edge ofa pixel where the organic light emitting array faces the thin filmtransistor array during joining, the black matrix layer 542 is formed ontransparent electrode layers of the first electrode pattern 2331, thesecond electrode pattern 2332 and the connection pattern 2332 cincluding the color filter layer 541. In the fifth embodiment, ascompared to the second embodiment, the first interlayer insulating filmmay be omitted.

Also, the black matrix layer 542 and the color filter layer 541 formedin different layers serve as exterior light shielding layer 5400.

FIG. 7E illustrates a touch electrode array of an organic light emittingdisplay according to a sixth embodiment of the present invention.Compared with the second embodiment, the sixth embodiment comprises anexterior light shielding layer 6400 including a black matrix layer 642and a color filter layer 641 under the metal bridge 231.

Meanwhile, according to the organic light emitting display of thepresent invention, the reason for forming the exterior light shieldinglayer using the black matrix layer and the color filter layer duringformation of the touch electrode array is as follows.

Through the array formation process, the black matrix layer is formed tohave a small thickness of 1 μm to 3 μm and is readily formed in apredetermined region through a printing process only, without using anymask. Accordingly, the black matrix layer is easily formed, absorbscertain colors of light according to individual wavelength bands andthus prevents reflection and recognition of exterior light incident uponthe organic light emitting display by the electrode of the organic lightemitting diode. Also, a combination of a circular or linear polarizingplate and a phase-retarder layer which is required for organic lightemitting displays and has a large thickness can be omitted andflexibility and thinness of organic light emitting displays can thus beeasily realized. Generally polarizing plates have a thickness of about150 μm or more. This thickness can be reduced and great effects ofimprovement in transmittance and reduction in thickness can thus beobtained.

Also, in a case in which the circular polarizing plate or the like isprovided, an organic film requiring light-isotropy is used as the etchstopper layer in order to compensate a viewing angle. The presentinvention does not require this organic film, thus enabling use of ageneral organic film incapable of performing optical compensation.Accordingly, an expensive optical film can be omitted and costs can thusbe reduced.

Also, the black matrix layer and the color filter layer used for theexterior light shielding layer can alternate interlayer insulatingfilms, thus enabling formation of a touch electrode array withoutincrease in thickness and addition of separate processes.

Meanwhile, the afore-mentioned embodiment as well as a modifiedembodiment as shown in FIG. 8 may be used.

FIG. 8 is a sectional view illustrating an organic light emittingdisplay according to a modified embodiment of the present invention.

In comparison with the fifth embodiment, in the modified embodimentshown in FIG. 8, the black matrix layer 701 is formed, instead of a bankto isolate respective pixels, on the organic light emitting array 150formed on the first buffer layer 130 and thin film transistor array 140which face the black matrix layer 701.

In this case, the black matrix layer is not further provided in order toprevent recognition of exterior light and the black matrix layer 701 isdisposed instead of the bank, thus having an advantage of processsimplification.

In this case, in order to prevent recognition of exterior light, theblack matrix layer 701 is formed on the thin film transistor array 140and the color filter layer 541 is formed in the touch electrode array230.

Non-described reference numeral “703” represents a second electrode ofthe organic light emitting array 150 and 702 (702 a, 702 b and 702 c)represents a light emitting layer provided in each pixel.

In this case, the remaining first electrode of the organic lightemitting diode may be formed on the thin film transistor array 140.

FIG. 9 is a reference embodiment of the present invention compared withthe organic light emitting display in terms of visibility.

In comparison with the embodiment shown in FIG. 3, the referenceembodiment of FIG. 9 further includes a polarizing plate 2000 inside thecover glass 3000 and excludes an exterior light shielding layer in thetouch electrode array 230. The remaining components having the samereference numeral as in FIG. 3 have the same configurations and adetailed description thereof will be omitted.

Reflectivity and transmittance values obtained by simulating theconfigurations shown in FIGS. 3 and 9, actual transmittance underconditions of exterior light at 320,000 cd and transmittance of organiclight emitting diode of 500 nit are shown in Table 1 below.

TABLE 1 Reference Present embodiment invention Simulation Reflectivity  0% 3.3% Transmittance  40%  90% Actually measured Reflectivity (underMeasured data: Measured data: 320,000 cd) 20777 cd 26755 cd 6.5% 8.4%Transmittance Measured data: Measured data: (under 500 nit) 190 nit 440nit  38%  88%

As can be seen from Table 1 above, in this simulation, when an apertureratio is 10%, in the reference embodiment, reflectivity andtransmittance are determined as 0% and 40%, respectively, regardless ofaperture ratio, depending on polarizing plate properties. Also,reflectivity of the present invention is determined by reflectivity of aregion corresponding to the color filter layer, which corresponds toabout 3.3% obtained by the equation of 10%*⅓. Also, in the simulation ofthe present invention, transmittance is about 90% when the color filterlayer corresponds to the light emitting layer having the same color.

The values obtained by the simulation are ideal values which areslightly different from measured values.

That is, under exterior light of 320,000 cd, reference embodimentreflects light of 20,777 cd which is 6.5% greater than the simulationvalue, 0%, and the present invention reflects light of 26,755 cd, whichcorresponds to 8.4% which is slightly larger than a simulated value,3.3%. This difference in values is caused by reflection to other layers,in addition to the touch electrode array. These values are 10% or less,such that a viewer does not see exterior light. From the actuallymeasured values of the reference embodiment and the present invention,recognition of exterior light is prevented.

Also, actually measured transmittance of the reference embodiment andthe present invention is obtained by testing at an organic lightemitting diode brightness of 500 nit. That is, when brightness of theorganic light emitting diode disposed under the touch electrode array is500 nit, the reference embodiment has a measured value of 190 nit andhas a transmittance efficiency of about 38% due to presence of thepolarizing plate having a strong light-absorbing property, while thepresent invention has a measured data of 440 nit and has a transmittanceefficiency of 88% due to use of the color filter layer having superiortransmittance.

That is, as can be seen from the simulation and actual measurement, thepresent invention and the reference embodiment have similarreflectivity, but the present invention has considerably highertransmittance.

Hereinafter, a method for fabricating an organic light emitting displayaccording to the present invention will be described with reference toFIGS. 2 to 6.

First, a first etch stopper film 120, a first buffer layer 130, a thinfilm transistor array 140 including a thin film transistor formed ineach of a plurality of pixels defined in a matrix form in an activeregion of the first buffer layer 130, and an organic light emittingarray 150 including an organic light emitting diode connected to thethin film transistor of each pixel are formed on a first substrate (notshown).

Also, a protective film 160 is formed such that it covers the organiclight emitting array 150. This protective film 160 may be omitted, ifdesired.

Also, a second etch stopper film 210 and a second buffer layer 220 areformed on the second substrate 200.

Then, first and second touch electrodes intersecting each other, and atouch electrode array 230 including a black matrix layer 242 and a colorfilter layer 241 are formed on the second buffer layer 220. Duringformation of the touch electrode array 230, a touch pad portion 2350including a plurality of touch pads 2351 b is formed in a part of thedead region. A detailed description and various embodiments associatedwith formation of the touch electrode array 230 can be seen from FIGS.5, 7 a to 7 e and 8.

Then, an adhesive layer 400 is interposed between the protective film160 that covers the organic light emitting array 150 and the touchelectrode array 230 and a joining process is performed. In this process,a sealant 450 including a conductive ball 455 is applied to the touchpad portion 2350 and the conductive ball 455 bonds the touch pad portion2350 disposed on the second buffer layer 220 to a dummy pad of the thinfilm transistor array 140 disposed on the first buffer layer 130.

Then, the first substrate and the second substrate 200 are removed vialaser irradiation or using an etching solution.

Then, a film substrate 1000 is adhered to the exposed first etch stopperfilm 120 via an adhesive layer 110 and the exposed second etch stopperfilm 210 is covered with a cover glass 3000. Here, an adhesive layer mayalso be interposed between the second etch stopper film 210 and thecover glass 3000.

For realization of flexibility and thinness of displays, as recenttrends, the organic light emitting display of the present invention ischaracterized in that a layer having the same function of preventingrecognition of exterior light as the polarizing plate is formed duringthe touch electrode array formation process, instead of the polarizingplate. As a result, realization of ultra-slim organic light emittingdisplays is possible.

The organic light emitting display and the method for fabricating thesame according to the present invention have the following effects.

First, the black matrix layer is readily formed to have a smallthickness of 1 μm to 3 μm through an array formation process. Also, acombination of a circular polarizing plate or a linear polarizing plateand a phase-retarder layer requires a large thickness for organic lightemitting displays of related art. However, in the present invention, thepolarizer for preventing exterior light can be omitted. Also,flexibility and thinness of organic light emitting displays can thus beeasily realized. Generally polarizing plates have a thickness of about150 μm or more, but this thickness can be reduced and great effects ofimprovement in transmittance and reduction in thickness can thus beobtained.

Second, the black matrix layer and the color filter layer can be readilyformed through a printing process only, without using any mask.

Third, the black matrix layer can be easily formed, further can absorbcolors of light according to individual wavelength bands and thusprevents reflection and recognition of exterior light incident upon theorganic light emitting display by existing the electrode in the organiclight emitting diode. As compared to a structure using a polarizingplate, the structure according to the present invention has similarreflectivity and improved transmittance of a device and thus improvedoptical efficiency.

Fourth, in a case in which the circular polarizing plate or the like isprovided, an organic film requiring light-isotropy is used as the etchstopper layer in order to compensate a viewing angle. The presentinvention does not require this organic film, thus enabling use of ageneral organic film incapable of performing optical compensation.Accordingly, an expensive optical film can be omitted and the cost canthus be reduced.

Fifth, the black matrix layer and the color filter layer used for theexterior light shielding layer can alternate interlayer insulatingfilms, thus enabling formation of a touch electrode array withoutincrease in thickness and addition of separate processes.

Sixth, the organic light emitting display of the present invention is ofan in-cell type in which the touch electrode array is included in thecover glass, thus requiring no separate process for attaching atouchscreen thereto and thus enabling realization of slim displaysfabricated through a simple process.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A method for fabricating an organic lightemitting display comprising: forming a first etch stopper film and afirst buffer layer on a first substrate, and forming a thin filmtransistor array comprising a thin film transistor in each of aplurality of pixels defined in a matrix form and an organic lightemitting diode connected to a thin film transistor of each pixel in anactive region of the first buffer layer; forming a second etch stopperfilm and a second buffer layer on a second substrate; forming a touchelectrode array on the second buffer layer, wherein the touch electrodearray comprises first and second touch electrodes intersecting eachother, and an exterior light shielding layer comprising at least a colorfilter layer; joining the first and second substrates via an adhesivelayer between the organic light emitting diode and the touch electrodearray; removing the first substrate and the second substrate; andadhering a film substrate to the exposed first etch stopper film andcovering the exposed second etch stopper film with a cover glass.
 2. Themethod according to claim 1, further comprising forming a black matrixlayer within the exterior light shielding layer.
 3. The method accordingto claim 2, wherein the forming the touch electrode array comprises:forming a metal bridge on the second buffer layer; forming a firstinterlayer insulating film comprising a contact hole at both ends of themetal bridge on the second buffer layer; patterning a transparentelectrode on the first interlayer insulating film, to form a pluralityof first electrode patterns connected through the contact hole to themetal bridge in an island shape in a first direction, and a plurality ofsecond electrode patterns, each having the same shape as each of thefirst electrode patterns, and forming a connection pattern to integrallyconnect adjacent second electrode patterns.
 4. The method according toclaim 3, further comprising: forming a second interlayer insulating filmon the first interlayer insulating film including the plurality of firstelectrode patterns, the plurality of second electrode patterns and theconnection pattern; and forming a common transparent electrode patternthat covers the plurality of first electrode patterns, the plurality ofsecond electrode patterns and the connection pattern, on the secondinterlayer insulating film.
 5. The method according to claim 3, whereinforming the black matrix layer and the color filter layer is processedduring the forming a first interlayer insulating film.
 6. The methodaccording to claim 4, wherein forming the black matrix layer and thecolor filter layer is processed during the forming a second interlayerinsulating film on the first interlayer insulating film.
 7. The methodaccording to claim 4, wherein forming one of the black matrix layer andthe color filter layer is processed during the forming a firstinterlayer insulating film and forming the other is processed during theforming a second interlayer insulating film on the first interlayerinsulating film.
 8. The method according to claim 3, wherein forming theblack matrix layer and color filter layer is processed directly on thesecond buffer layer before the forming a metal bridge on the secondbuffer layer.
 9. The method according to claim 4, wherein forming theblack matrix layer and the color filter layer are processed on thecommon transparent electrode pattern after the forming a commontransparent electrode pattern that covers the plurality of firstelectrode patterns, the plurality of second electrode patterns and theconnection pattern.
 10. The method according to claim 1, wherein thestep of removing the first substrate and the second substrate is carriedout by etching or laser-irradiating the first substrate and the secondsubstrate.